XRAY - Model racing cars

I had my XT809 out yesterday for the first time since November. The RB fired within the first half a second of fuel hitting the carb.
Since I wasn't at a prepared track but just really REALLY dry and loose dirt the truck couldnt find traction anywhere but at an idle...lol
The issue:
About half way through the first tank I started noticing an odd noise over the sound of the pipe. Only on-throttle hard. Im guessing the diffs but after a few years of owning two or three Savage Monster trucks I am certain if there was that type of trouble inside the diffs they wouldnt have held the punishment they took yesterday. The noise sounds more abraisive than crunchy; similar to a brushless electric car but without the rocks...lol
What could be making this noise?
Obviously I need to tear into the truck and clean it all up anyway, but cleaning it is different "right now" than full on wrenching. My excuse is a broken hand and this contraption on it that severely limits my gripping ability on my right hand. Lucky to be a lefty I suppose except the fact its a right handed world...
The point being I'd like a clue as to where to start looking rather than full-on disassembly. A season-opener in Novelty Mo is coming up May 1 and I want to be ready.

See if it happens under hard braking too. I'm guessing your brakes are set quite soft on a loose surface so do it on the bench, and try to push it with wheels locked up. Any crunching could indicate a pinion jumping over a diff because of a worn or collapsed bearing.

I do not recall hearing the noise under hard braking. The brakes aren't "set" to anything persay other than the instruction(s) I used. I installed the Dynamite linkage setup from the beginning when I built this kit last August/September. It has only seen Nitro about three times. Once for running in the engine which I did all in one day. And twice on the dirt. So I would hope to think the bearings are still in new condition. I suspect it may be the clutch spring rubbing the inside of the clutchbell. Its the only thing I can imagine that would make that type of sound.
My todo list this week includes a good cleaning and checking over of the XT809.If I find anything I'll let you know. Thanks for your response. I was beginning to wonder if anyone was reading it.....

You probably would not here a clutch spring or shoe dragging or rubbing, the tale sign there is the wheels continually spinning & engine cuts under breaking.
If its only under hard throttle could be diffs slipping on the gears or jumping. A quick check is to put a driver into the centre diff outdrives & then try & turn the front then rear wheels, if it clicks its to loose. Its very rare to hear them jumping under throttle its normally more prominent under braking.

I think its a strip down job & slowly check things.

Your engine did you after run it, as if left for that period of time with out oil you bearings could be rusty. Again though bearing noise is normally more prominent on tick over.

Some, if not most of you will cringe, but no, I did not use after-run oil. The truck was spankin new when I took it to the track in November and it made "the noise" that day as well. The truck by any other standard runs well, steers well, and started up better after sitting unattended than any other engine I have had these last ten years.

I agree, though, that I need to disassemble the truck and look it over. The slowly part is a given with my right hand being broken. This ought abe an experience.....one-handed wrenching....

clutch bell bearings or bearings SOMEWHERE in your car. I know that noise all too well. It happened to me once when I was testing my car and then it came to an abrupt stop and when I checked all the diffs seemed to move, but not move forward together. I checked for rocks and nothing, I checked for something the spur gear may have caught and still nothing. I took out the motor and it was the clutch bell bearings. Seriously chewed up. They were brand new too, who knows why that may have happened.

But from what youve described its definitely a bearing issue.Youll find the culprit bearing soon Im sure.

Well I guess stranger things have happened than to have gotten a bad bearing or two from the getgo. If I DO happen to find a bad bearing, I will be surely disappointed as I was led to believe these kits are very closely monitored and checked for things like this.

That said, does anyone have a list of all bearings by size needed for the XT809?

I approach these issues like killing a cricket. Just stomp on it rather than molly-coddle the issue. I'll replace every bearing in the truck with some Avid bearings and be done with the worry.
I know clutchbell bearings are a very regular replacement maintenance item. But to have the factory set not last an hour past break-in is a bit ridiculous. Considering breakin was done on clean concrete. This noise appeared within the first two or three laps on a real track last November.
I'll report my findings when I get it all tore apart. But that isn't going to happen until all the replacement bearings have arrived.

Its hardly breaks applying when the throttle is fully open is it? (Just noticed you found it was bearings! see below re clutch shimming)
As the servo has to push the brake rods on full throttle you dont have some silicone tubing both sides of the brake hook if you know what I mean e.g. to prevent brakes being sticky Ive heard some people but a piece of tubing on the opposite side of the brake clamp. (e.g to give them feel! (but in this case you might have it both sides??))

Get a clutch shimming kit and your bearings will last much much longer Ive just had mine in for 3 days (that was by accident as I hadnt time to change them really.)
Thats 3 days racing not just sitting in the buggy lol!

Nick

I think I get what you'r etrying to say and I will check for that. I admittedly have a linkage issue with th ebrake adjustment screws I am not happy with. And it involves fuel tubing.

Thanks for the tip in that direction.